By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.
Move over gluten. There’s another dietary “demon” looking to overtake your perch as the “ingredient-du-jour” that we should be avoiding. It’s called lectin, and going “lectin-free” seems to be the newest trend in dieting. Many believe a lectin-free lifestyle can reverse or cure diseases, and some celebrities have even jumped onboard, claiming their health improved dramatically since cutting out lectins.
So what’s the deal with lectins? Are lectins really bad for you? Well, my view on lectins is similar to how I feel about gluten. Some people may very well benefit from limiting lectins. For the vast majority, though, they are perfectly fine and don’t pose any significant problems. Let me explain what lectins are and why I believe they’re not necessarily as troublesome as some would have you believe…
What Are Lectins?
Lectins are a type of protein found in plants that bind to carbohydrates. Plant foods high in lectins include corn, milk, legumes (beans, lentils, and peas), nuts (peanuts and cashews), seeds, grains, nightshades (eggplant, peppers, potatoes, and tomatoes), squashes, and certain fruits (mainly their seeds).
There are countless types of lectins, and researchers are still trying to figure out what all of these various compounds are capable of.
There’s some research indicating lectins could have important health benefits. A few studies point to possible antimicrobial effects and anticancer activity. And in a more “everyday” capacity, lectins bind to carbohydrates during the digestive process, helping to reduce their effects on blood sugar. This is obviously a boon for those with diabetes.
On the flip side though, the same binding characteristic of lectins is what some experts say can make them so harmful.
Lectins and Inflammation
Though scientists have known about lectins for a long time, they were introduced to the general public by California cardiologist Steven Gundry, MD. Dr. Gundry is an integrative cardiologist whose focus in his practice has been dietary and lifestyle changes to improve heart health. In his 2017 book, The Plant Paradox, he connects lectins with a wide range of health problems, including autoimmune conditions, heart disease, diabetes, and neurodegenerative issues.
It’s Dr. Gundry’s belief that the binding of lectins to carbs in the body can interrupt proper communication between cells, which can lead to inflammatory reactions. Also, because “clingy” lectins attach themselves to the intestinal wall, problems can arise in people whose guts aren’t in the best of health. The intestinal wall can become more permeable, allowing food particles and other toxins to seep into the bloodstream, triggering inflammation as the body fights off these foreign invaders. (This is commonly referred to as “leaky gut.”)
Indeed, some research links lectins to inflammation (the root cause of countless diseases, including those mentioned above) and other harmful processes. In one study, researchers stated that, when lectins bind to cells lining the digestive tract, harmful local and systemic reactions take place. For this reason, they classified lectins as “antinutrients” and toxins. They continued, “Locally, [lectins] can affect the turnover and loss of gut epithelial cells, damage the luminal membranes of the epithelium, interfere with nutrient digestion and absorption, stimulate shifts in the bacterial flora and modulate the immune state of the digestive tract. Systemically, they can disrupt lipid, carbohydrate and protein metabolism, promote enlargement and/or atrophy of key internal organs and tissues and alter the hormonal and immunological status.”
Sounds confusing, right? After all, the veggies, legumes, nuts and seeds that contain lectins have long been cited by nutrition experts as some of the healthiest foods we can eat.
Should You Eliminate Lectins?
Clearly, the research is conflicting. Should you forgo lectins, or is it OK to eat lectin-containing foods?
The short answer is that for a small subset of people, avoiding lectin-rich foods is a good idea.
In those with chronic digestion problems (such as an inflammatory bowel disease or irritable bowel syndrome) or certain autoimmune conditions (like rheumatoid arthritis), eliminating foods high in lectins could alleviate unpleasant digestive or systemic symptoms.
Some people may also have a lectin allergy or sensitivity. In these cases, the allergic reaction is usually pretty immediate and can be severe. Of course, these folks would want to avoid lectin as much as possible. Lectin sensitivities or allergies can be genetic, but a lot of them develop later in life in patients who have compromised gastrointestinal systems.
(If you’re curious if you have a sensitivity, you can try an elimination diet. Cut out foods high in lectins, then slowly reintroduce them, one at a time, and watch for symptoms.)
But for the vast majority of people who are otherwise healthy, foods high in lectins are perfectly safe to eat. In fact, it’s my belief that eliminating all lectin-rich foods from your diet, if you really don’t need to, is a bad idea. It forces you to avoid a vast array of nutritious, fiber-rich, health-promoting plant foods—and in the long run, the lack of variety could negatively affect you and your well-being.
How to Remove Lectins in Food
Moreover, if you’re really concerned about lectins, you don’t necessarily have to cut out these foods forever. The simple process of cooking can actually deactivate lectin and its potentially harmful effects.
Soaking beans overnight in water and some baking soda, then draining them and thoroughly boiling or pressure cooking them, can eradicate nearly all lectins. In fact, pressure cooking vegetables and legumes is also an excellent way to decrease lectin content in those plant foods.
Likewise, sprouting grains, seeds, and beans releases enzymes that reduce lectins, and the process of fermentation can cut the lectins in dairy and vegetables.
Bottom line, for some people, a lectin-free diet makes sense. But for the majority, I don’t think it’s worthwhile. As I’ve mentioned many times in the past, the key to a good diet or eating plan is how sustainable it is…meaning, is it something you can follow for the rest of your life, and also thrive on? And does it provide you with all the vitamins, minerals, and nutrients to stay healthy? A lectin-free diet removes such a large number of beneficial, nutritious foods from your diet that I don’t think it’s sustainable long term.
Balance is the key to life, and it’s the best way to approach diet, too. This is why my “diet” recommendation always has been, and will continue to be, the PAMM diet.
- Gundry, S. 15 Ways to Reduce Lectins In Your Diet. Gundrymd.com, May 23, 2017.
- Lagarda-Diaz I, et al. Legume lectins: proteins with diverse applications. Int J Mol Sci. 2017;18(6).
- De Mejia EG and Prisecaru VI. Lectins as bioactive plant proteins: a potential in cancer treatment. Crit Rev Food Sci Nutr. 2005;45(6):425-45.
- Vasconcelos IM and Oliveira JT. Antinutritional properties of plant lectins. Toxicon. 2004 Sep 15;44(4):385-403.
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